From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2 for 4.5] arm32: fix build after 063188f4b3 Date: Tue, 14 Oct 2014 13:43:50 +0100 Message-ID: <543D1A86.8010001@linaro.org> References: <1413214141-370-1-git-send-email-julien.grall@linaro.org> <1413278157.1497.13.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1Xe1SJ-00071l-45 for xen-devel@lists.xenproject.org; Tue, 14 Oct 2014 12:43:59 +0000 Received: by mail-wi0-f172.google.com with SMTP id n3so10009486wiv.5 for ; Tue, 14 Oct 2014 05:43:57 -0700 (PDT) In-Reply-To: <1413278157.1497.13.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: xen-devel@lists.xenproject.org, tim@xen.org, Jan Beulich , stefano.stabellini@citrix.com List-Id: xen-devel@lists.xenproject.org On 10/14/2014 10:15 AM, Ian Campbell wrote: > On Mon, 2014-10-13 at 16:29 +0100, Julien Grall wrote: > >> +GLOBAL(do_smc) > >> +GLOBAL(do_smc) > > These should both be ENTRY. Why? Is it because GLOBAL should be used for variable and ENTRY for function? >> +int do_smc(register_t function_id, ...); > > Are you sure that the variadic function calling convention is the same > as for a regular function call? I'm not entirely clear having read > AAPCS, it says they are marshalled according to "the standard base". All the parameters fits in a register, so the compiler will effectively use the first registers to pass arguments. This may be an issue if the user decides to pass an uint64_t on ARM32. > I think it would probably be safer to declare this guy as taking 3-4 > arguments and pass in 0 for the unused one. You could wrap in > do_smc() helpers if you really wanted. I will introduce helpers. It will be easier if we decide to extend the number of parameters (SMC64 supports up to 5 parameters). > I'd prefer to name this call_smc, do_foo tends to be used on the callee > side of exception things (e.g. do_hypervisor_trap etc, do_psci_blah). Will make the change in the next version. Regards, -- Julien Grall